OTTAWA (Reuters) - A Canadian woman managed to survive for three days buried deep in a snowbank, most likely because the snow helped to insulate her, police said on Tuesday.

Donna Molnar, 55, was last seen on Friday when she left her home west of Toronto in a snowstorm to get baking supplies. Her van was found abandoned by the side of a windswept rural road late the next day.

Police scoured the nearby area for two days and said they had all but given up hope on Monday when a search dog called Ace began to bark at a snowdrift about 200 meters (220 yards) from where the van had been found.

Rescuers approaching the spot found Molnar, who was suffering from hypothermia. She is now in hospital in serious but stable condition.

"That deep snow may very well have been what insulated her enough to keep her core temperature high enough that she survived the three days," said Staff Sergeant Mark Cox of the police force in Hamilton, Ontario.

Cox told the Canadian Broadcasting Corp that it appeared Molnar had become disoriented in the snowstorm and may have left her vehicle to get help.

"I have to admit that we were losing hope that we'd find her alive ... we felt that we might simply be trying to give closure to the family at that point," Cox said.

And what of Ace, the search dog?

"I'm told on good authority he's looking at a T-bone dinner for this one," Cox said.